*{
    margin:0;
    padding:0;
    list-style: none;
}
html{
    font-size:20px;
}
.wrap{
    width:18rem;
    height:32rem;
}
.bcg{
    width:18rem;
    height:32rem;
    background:url(../img/start.png) no-repeat;
    background-size: 100%;
    position:relative;
}
.playGame {
    width: 7rem;
    height: 2rem;
    line-height: 2rem;
    border: 0.2rem solid red;
    background: none;
    text-align: center;
    color: red;
    left: 5rem;
    bottom: 5rem;
    position: absolute;
    font-weight: bolder;
}